Sonar systems have long been used by anglers to gauge conditions in a given fishing location, such as the depth of the body of water being fished, as well as the presence and depth of fish (commonly referred to as a “depth finder” or a “fish finder”). Sonar systems use a transducer (e.g., electroacoustic transducer) to generate a sonar pulse that is directed down through the water. The transducer receives a sonar echo return from the bottom of the body of water, as well as sonar returns from fish or other objects in the water and located within the transducer's sonar cone. The depth (or distance) and size of solid objects (e.g., fish, lure, bottom of the body of water, etc.) are then estimated based upon the speed and intensity of the echo return waves relative to the original sonar pulse. The estimated information is then signaled to a display.
Sonar based fish finders have been devised for use by fishermen from a river bank or a shore. Exemplary of these are those shown and described in U.S. Pat. Nos. 5,463,597; 5,495,689; 5,546,695; 5,887,376 and 6,122,852. These fish finder systems typically consist of a float or buoy that supports a sonar, with the float tethered to a fishing pole. A transmission line extends from the float to a display screen that is located beside the shore based fisherman. With this system, a fisherman is able to see sonar returns from fish and the immediate bottom terrain received and relayed from the buoy while standing on the bank of the body of water. The buoy may be located over the angler's baited hook or even be on the fishing line itself. These tethered systems have many limitations, including the requirement of a tethered transducer to a display.
Recently, portable fish finder devices for use by an angler have been devised. Examplary of these are U.S. Pat. Nos. 6,693,847; 6,771,562 and 7,554,884. These portable fish finder devices are contained within a buoyant housing. With this system, the load housed within the housing includes sonar operatively linked by a microprocessor with a radio transmitter. These housings, however, have shortcomings when used during fishing, such as in rough or choppy water where the transducer is continuously rocked from side-to-side as the device is bobbed in an up-and-down direction within the water. Further, these housings are not conducive to having the load maintained in a vertical position in a body of water where there is a water-current or the buoyant housing is moved through the body of water, such as when an angler is trolling, which can be in conditions of a water-current or rough/choppy water. In each of these situations, the housing does not adequately maintain the transducer in a desired vertical position, which is desired to maintain a connection with the sonar display and provide accurate sonar data, which is then provided to the angler on a display.
In light of the above, a need exists for a housing for a fish finding device that is capable of maintaining the transducer in a vertical position to provide a desired connection and provide accurate sonar data when the fish finder is used in typical fishing water conditions, such as choppy and/or wavy water, water-current, or the fish finder being moved through a body of water during an activity such as trolling.